Tuesday, May 29, 2007

Roarke's New and Hot (Week 9)

A collection of papers soon to be published in the journal Physiological and Biochemical Zoology presents a new methodology that can be used to observe evolution in action. By studying the rapidly evolving E.coli bacteria, the scientists performing these studies are able to gain new insights into how organisms are able to adapt to environmental changes and fluctuations. These particular studies focused on how E.coli evolves to deal with changes in acidity, which is relevant to the occupation of human intestines by the bacteria.

The scientists had four experimental groups: one exposed to a constantly acidic environment, one to a constantly basic environment, one to a randomly fluctuating environment, and one to an environment that changed from acidic to basic every 24 hours. Each group was left in its experimental environment for 1000 generations and then tested in acidic and basic environments. The researchers found that the groups placed in a constant environment survived well in the environment they had been exposed to, while the groups placed in fluctuating environments performed well in both acidic and basic environments. As the article states, this demonstrated that the "jack-of-all-trades" can be the master of some as well.

While this is only one study that can be done using E.coli as a model, it opens the door to many other new studies of how rapidly evolving populations can quickly adapt to new environments. Exciting stuff!